Tag: sun

Parker data downloaded from first two orbits

9:28 am

The science team for the Parker Solar Probe has completed the download of all data gathered during the spacecraft’s first two solar orbits.

On May 6, 2019, just over a month after Parker Solar Probe completed its second solar encounter, the final transmission of 22 gigabytes of planned science data — collected during the first two encounters — was downlinked by the mission team at the Johns Hopkins Applied Physics Laboratory, or APL, in Laurel, Maryland.

This 22 GB is 50% more data than the team had estimated would be downlinked by this point in the mission — all because the spacecraft’s telecommunications system is performing better than pre-launch estimates. After characterizing the spacecraft’s operations during the commissioning phase, which began soon after launch, the Parker mission team determined that the telecom system could effectively deliver more downlink opportunities, helping the team maximize the download of science data.

The team has capitalized on the higher downlink rate, instructing Parker Solar Probe to record and send back extra science data gathered during its second solar encounter. This additional 25 GB of science data will be downlinked to Earth between July 24 and Aug. 15.

Don’t expect any immediate press conferences announcing results. It will take them time to analyze this batch, and they will probably want to do a few more orbits before coming to any conclusions.

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Sunspot update June 2019: Down to zero again, with next cycle making an appearance

11:54 am

Below is the June graph of sunspot activity released by NOAA yesterday. As I do every month, I am posting it here, annotated to give it some context.

After three months of slightly increased sunspot activity, the Sun in June was essentially blank, with sunspots visible on its facing hemisphere on only five days. In addition, the 36 day stretch of spotless days that began in May and stretched through most of June was the longest such stretch since the last minimum in 2009.
June 2019 sunspot activity

The graph above has been modified to show the predictions of the solar science community for the previous solar maximum. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction, extended in November 2018 four years into the future.

Even while the solar minimum continues and heads for its low point, the first indications of the next solar solar cycle have appeared:
» Read more

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DSCOVR in safe mode

9:25 am

The solar wind monitoring satellite DSCOVR has gone into safe mode.

It is at present unclear what the problem is, or whether they can recover the spacecraft.

DSCOVR’s history is packed with political shenanigans. It was first proposed by Gore as Triana, with its only purpose to take global pictures of the Earth so Gore and the left could use these images for environmental propaganda. Bush canceled it, partly because it really had no legitimate scientific purpose and partly to prevent the left this propaganda tool. It was resurrected during the Obama administration but with a more useful purpose, providing early solar wind data so that Earth-based power grids could get prepared should a major solar storm be incoming. NASA’s other solar wind monitors ACE and SOHO, were already decades beyond their planned lifespan, and the space agency, the solar weather community, and especially the world’s electrical power industry, was desperate to get a new satellite in space.

Ironically, with DSCOVR’s shutdown we are still dependent on ACE and SOHO. Nor is there any replacement satellite anywhere close to launch.

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New prediction for upcoming solar cycle

6:20 pm

The uncertainty of science: A new prediction for the upcoming solar cycle, announced today, calls for a much weaker cycle then the general consensus of the solar science community.

The new prediction:

The forecast for the next solar cycle says it will be the weakest of the last 200 years. The maximum of this next cycle – measured in terms of sunspot number, a standard measure of solar activity level – could be 30 to 50% lower than the most recent one. The results show that the next cycle will start in 2020 and reach its maximum in 2025.

The consensus prediction:

[They] dutifully tabulate the estimates, and come up with a peak sunspot range: 95 to 130. This spells a weak cycle, but not notably so, and it’s marginally stronger than the past cycle. [They do] the same with the votes for the timing of minimum. The consensus is that it will come sometime between July 2019 and September 2020. Maximum will follow sometime between 2023 and 2026.

The main difference is that the consensus expects the next maximum to be weak but stronger than the maximum that just ended, while the new prediction says the next maximum will be the weakest in 200 years.

It has been my impression that there is unhappiness in the solar science community over the consensus prediction. I suspect today’s independent prediction is an indication of that unhappiness. The scientists involved in this research wanted to go on record that they disagree with the consensus.

I expect that NOAA will eventually put the consensus prediction on their monthly sunspot graph that I post here each month. If they do, I might also add this independent prediction so that we can compare the accuracy of the two as the next cycle unfolds.

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Sunspot update May 2019: The long ramp down

12:18 pm

NOAA yesterday released its May update for the Sun’s sunspot cycle. The graph is posted below, annotated by me to give it some context.

The Sun in May continued to show the exact same amount of activity as it had shown for March and April. This steady uptick in sunspot activity once again shows that the ramp down to full solar minimum will be long and extended.

May 2019 sunspot activity

The graph above has been modified to show the predictions of the solar science community for the previous solar maximum. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction, extended in November 2018 four years into the future.

That we are definitely ramping downward to minimum, even with the slight increase in the past three months, is shown by the fact that the Sun has shown no sunspots for the past fifteen days. In fact, all the activity shown in May comes from the first half of the month. This pattern is actually a reflection of the Sun’s 27-day rotation period. As I noted in my February 2017 update,

January’s activity however illustrated a statistical phenomenon that is typical of the sunspot count. That count is determined not by the numbers of sunspots on the entire surface of the Sun, but on the sunspots visible on the side of the Sun facing the Earth. Since it is not unusual for one face to be more active than the other, as we transition from maximum to minimum the sunspot counts will often show a more pronounced up-and-down curve reflecting this fact. Since the Sun’s day equals about 27 Earth days, this means that about every two weeks the active side will dominate our view until it rotates away and the inactive side reveals itself for two weeks.

In 2017 the number of spots were greater, so the period of inactivity was generally less. Now, it is not unusual for the Sun to be blank for weeks at a time. When it does become active, it is also not unusual for that activity to be confined to one hemisphere, so we get two weeks or less of activity, followed by two weeks or more of blankness.

So far there have been no sunspots in June. Expect that to continue for at least another week, when the more active hemisphere of the Sun returns to face us. I would not be surprise however if that other hemisphere arrives with its sunspots gone, so that the present streak of blankness continues unabated.

Meanwhile, solar scientists struggle to figure out what is going to happen next. Unlike climate scientists, who know as little about the climate, the solar science community admits to its ignorance about the Sun, and the uncertainty of its solar models.

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Solar scientists struggle to predict the next sunspot cycle

9:10 am

Link here. This is a detailed article describing the meeting in March where the solar science community gathered to formulate its prediction for the next solar cycle.

What stands out about the meeting is the outright uncertainty the scientists have about any prediction they might make. It is very clear that they recognize that all their predictions, both in the past and now, are not based on any actual understanding the Sun’s magnetic processes that form sunspots and cause its activity cycles, but on superficial statistics and using the past visual behavior of the Sun to predict its future behavior.

“There’s not very much physics involved,” concedes panelist Rachel Howe of the University of Birmingham in the United Kingdom, who has been tasked with reviewing the mishmash of statistical models. “There’s not very much statistical sophistication either.”

Panelist Andrés Muñoz-Jaramillo of the Southwest Research Institute in Boulder agrees with Howe. “There is no connection whatsoever to solar physics,” he says in frustration. McIntosh, who by now has walked downstairs from his office and appears in the doorway, is blunter. “You’re trying to get rid of numerology?” he says, smirking.

The result, as I repeatedly note in my monthly sunspot updates, is that the last prediction failed, and that there is now great disagreement among these scientists about what will happen in the upcoming cycle.

[They] dutifully tabulate the estimates, and come up with a peak sunspot range: 95 to 130. This spells a weak cycle, but not notably so, and it’s marginally stronger than the past cycle. [They do] the same with the votes for the timing of minimum. The consensus is that it will come sometime between July 2019 and September 2020. Maximum will follow sometime between 2023 and 2026.

The range of predictions here is so great that essentially it shows that there really is no consensus on what will happen, which also explains why the prediction has still not been added to NOAA’s monthly sunspot graph. For past cycles the Sun’s behavior was relatively consistent and reliable, making such statistical and superficial predictions reasonably successful.

The situation now is more elusive. For the past dozen or so years the Sun has not been behaving in a consistent or reliable manner. Thus, the next cycle might be stronger, it could be weak, or we might be heading into a grand minimum, with no sunspots for many decades. These scientists simply do not know, and without a proper understanding of the Sun’s dynamo and magnetic field, they cannot make a sunspot prediction that anyone can trust.

And so they wait and watch, as we all. The Sun will do what the Sun wants to do, and only from this we will maybe be able to finally begin to glean an understanding of why.

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Sunspot update March 2019: An upcoming Grand Minimum?

10:04 am

Even though we are now deep into the beginning of what might become the first grand minimum in sunspot activity since the invention of the telescope, that does not mean the Sun has as yet stopped producing sunspots. Yesterday NOAA released its the monthly update of its tracking of the solar cycle, adding sunspot activity for March 2019 to its graph. Below is that graph, annotated by me to give it some context.

It shows the Sun with a slight burst in activity in March, suggesting that though we are now in the solar minimum that minimum still has the ability to produce sunspots.

At the same time, for me to say that we might be heading to a grand minimum, a time period lasting many decades where no sunspots are visible and the sunspot cycle essentially ceases, is not click bait or hyperbole. It is instead based on what I now think the solar science community is thinking, based on this very graph.

March 2019 sunspot activity

The graph above has been modified to show the predictions of the solar science community for the previous solar maximum. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction, extended in November 2018 four years into the future.

For past half dozen or so cycles the solar science community had issued its prediction for the upcoming solar maximum at about this stage in the overall cycle, during the final ramp down to minimum when it was clear that the Sun had entered that minimum.

This cycle’s prediction however has not yet happened, and in fact appears to be late. In fact, the extension of the May 2009 red curve that was made in November 2018 might very well be the only prediction we see. That extension is shown by the differences between the green 2007 prediction and the red 2009 prediction in the graph. Before November 2018 both curves ended at the same place, the end of 2018.

The extension of that red curve is important. As I noted in my December 2018 sunspot update,
» Read more

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Parker survives its second close Sun flyby

10:28 am

The Parker Solar probe has survived its second solar flyby, passing within fifteen million miles of the Sun on April 4.

It was moving at 213,000 miles per hour at that moment, which is probably a speed record for any human vehicle. That however is a record Parker will likely break on future fly-bys.

The entire close encounter runs from March 30 to April 10, during which the spacecraft gathers data about the Sun’s inner corona (the sun’s atmosphere).

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Parker about to do its second close fly-by of Sun

8:48 am

The Parker Solar Probe is now approaching its second close fly-by of the Sun, set to occur on April 4.

During this solar encounter phase, which lasts until April 10, the spacecraft’s four suites of science instruments are fully operational and storing science data collected from within the Sun’s corona. As designed, Parker Solar Probe will be out of contact with Earth for several days during the solar encounter. This allows the spacecraft to prioritize keeping its heat shield, called the Thermal Protection System, oriented towards the Sun, rather than pointing its transmitter towards Earth. Science data from this second solar encounter phase will downlink to Earth over several weeks later in spring 2019.

This fly-by the spacecraft will match the record of 15 million miles set during the first orbit as the closest any human spacecraft has ever gotten to the Sun. Future orbits however will get closer.

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Parker begins second orbit around Sun

8:43 am

The Parker Solar Probe has completed its first full orbit of the Sun and has begun full science operations.

On Jan. 19, 2019, just 161 days after its launch from Cape Canaveral Air Force Station in Florida, NASA’s Parker Solar Probe completed its first orbit of the Sun, reaching the point in its orbit farthest from our star, called aphelion. The spacecraft has now begun the second of 24 planned orbits, on track for its second perihelion, or closest approach to the Sun, on April 4, 2019.

Parker Solar Probe entered full operational status (known as Phase E) on Jan. 1, with all systems online and operating as designed. The spacecraft has been delivering data from its instruments to Earth via the Deep Space Network, and to date more than 17 gigabits of science data has been downloaded. The full dataset from the first orbit will be downloaded by April.

They have been somewhat tight-lipped about any results from the data already obtained. I suspect it has not yet been analyzed fully, and the scientists are reserving comment until they complete their first science papers and get them published.

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Parker reports in

9:09 am

Scientists have received confirmation from the Parker Solar Probe that it successfully survived its first close fly-by of the Sun and that all its instruments were able to gather data.

All Parker Solar Probe systems are operating well and as designed. The solid state recorder on the spacecraft indicated that, as planned, the four instrument suites had recorded a significant amount of data, which is scheduled to be downloaded to Earth via the Deep Space Network over several weeks starting Dec. 7. In addition to helping scientists begin to explore fundamental questions about the physics of our star, the data from this initial perihelion — collected closer to the Sun than any before — will help instrument teams calibrate Parker Solar Probe’s instruments and plan future observations.

Parker will repeat this many times over the next seven years. And while it will provide us a ton of new knowledge about the Sun, it will also be proving out technology that future solar system travelers will use to get closer such hostile environments.

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Powerful 1972 solar storm detonated ocean mines in Vietnam

10:12 am

Scientists studying a powerful 1972 storm have also uncovered a recently released Navy report that showed the storm was powerful enough that it detonated ocean mines off the coast of Vietnam.

On the same day [the storm arrived on Earth], while observing the coastal waters of North Vietnam from aircraft, US Navy personnel witnessed dozens of destructor sea mines exploding with no obvious cause. These mines were airdropped by the US Navy into Vietnamese waters as part of Operation Pocket Money, a mission aimed at blocking supplies from reaching North Vietnamese ports.

The Navy promptly investigated the peculiar explosions, working with the National Academy of Sciences and the National Oceanic and Atmospheric Administration, to conclude that more than 4,000 mine detonations were most likely triggered by the solar storm, Knipp said.

A now declassified report about the mining of North Vietnam from the Chief of Naval Operations at the Mine Warfare Project Office noted, “this was the first example of what happens to a major mining campaign in the face of the vagaries of nature.”

Many of the destructor mines were designed to trigger if they sensed changes in magnetic fields associated with moving ships. Solar activity is known to perturb Earth’s magnetic field, and in early August 1972, the perturbations were likely strong enough to meet the magnetic requirements for detonation, Knipp said.

This proves once again that one must not dismiss any possibility in trying to understand what happens in the universe. Don’t be credulous, but don’t be close-minded either. The universe can surprise you.

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Parker survives first close solar fly-by

4:05 pm

The Parker Solar Probe has successfully survived its first close fly-by of the Sun.

Mission controllers at the Johns Hopkins University Applied Physics Lab received the status beacon from the spacecraft at 4:46 p.m. EST on Nov. 7, 2018. The beacon indicates status “A” — the best of all four possible status signals, meaning that Parker Solar Probe is operating well with all instruments running and collecting science data and, if there were any minor issues, they were resolved autonomously by the spacecraft.

At its closest approach on Nov. 5, called perihelion, Parker Solar Probe reached a top speed of 213,200 miles per hour, setting a new record for spacecraft speed. Along with new records for the closest approach to the Sun, Parker Solar Probe will repeatedly break its own speed record as its orbit draws closer to the star and the spacecraft travels faster and faster at perihelion.

It will be several weeks before they can download all the data gathered during this first fly-by.

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Sunspot update October 2018: Deepening minimum

9:04 am

The monthly NOAA update of the solar cycle, covering sunspot activity for October 2018, was released yesterday. As I have done every month since this website began in July 2011, I am posting it below, annotated to give it some context.

Though there was a tiny uptick in sunspot activity on the Sun in October, the uptick was inconsequential. Overall, the activity in the past few months appears to closely match the weak activity seen in late 2007 and early 2008, just when the last solar minimum began.

October 2018 sunspot activity

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

As I noted in August, the NOAA graph is now getting very close to its right edge, which ends in December 2018. They will very soon have to update this graph so that it can take us into the next solar cycle. While they must do this, it will unfortunately end the standard visual used by them for more than a decade for showing the progress of the solar cycle. Depending on how they change it, I might be able adapt it to include this graph to allow a continuation of the same visual into the future. We will have to see.

Having seen now the full solar maximum for this cycle (weak and short), we are now moving to the next question: Will the developing solar minimum be as long and as deep as the last? Will it evolve into a grand minimum, lasting decades, as some solar scientists believe?

Or will the Sun return to the higher levels of activity seen during most of the 24 solar cycles observed since the last grand minimum in the 1600s?

Since our understanding of these changes is very poor, your guess is likely as good as anyone else’s. All we can really do is keep our eyes open and watch what happens.

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Parker begins first perihelion fly-by of Sun

9:10 am

It’s getting hot in here: The Parker Solar Probe has begun its first close orbital fly-by of the Sun, set to last from now until November 11.

This solar encounter encompasses the first perihelion of the mission, the point at which Parker Solar Probe is closest to the Sun. Perihelion is expected at about 10:28 p.m. EST on Nov. 5. The spacecraft will come within 15 million miles of the Sun’s surface and clock in at a top speed of 213,200 miles per hour relative to the Sun — setting new records for both closest solar approach and top heliocentric speed by a spacecraft. At perihelion, Parker Solar Probe will fly through material at about 3.6 million degrees Fahrenheit — but because material in this region is so tenuous, it doesn’t influence the temperature of the spacecraft. However, the Sun’s intense radiation heats the Sun-facing side of the spacecraft’s heat shield, called the Thermal Protection System, to about 820 F.

For several days around the Nov. 5 perihelion, Parker Solar Probe will be completely out of contact with Earth because of interference from the Sun’s overwhelming radio emissions.

The article provides some nice details about the spacecraft’s design.

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Parker sets new records in its flight to the Sun

9:19 am

The Parker Solar Probe has set two new space records, first for making the closest approach to the Sun as well as becoming the fastest spacecraft ever.

The spacecraft passed the current record of 26.55 million miles from the Sun’s surface on Oct. 29, 2018, at about 1:04 p.m. EDT, as calculated by the Parker Solar Probe team. The previous record for closest solar approach was set by the German-American Helios 2 spacecraft in April 1976. As the Parker Solar Probe mission progresses, the spacecraft will repeatedly break its own records, with a final close approach of 3.83 million miles from the Sun’s surface expected in 2024.

“It’s been just 78 days since Parker Solar Probe launched, and we’ve now come closer to our star than any other spacecraft in history,” said Project Manager Andy Driesman, from the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “It’s a proud moment for the team, though we remain focused on our first solar encounter, which begins on Oct. 31.”

Parker Solar Probe is also expected to break the record for fastest spacecraft traveling relative to the Sun on Oct. 29 at about 10:54 p.m. EDT. The current record for heliocentric speed is 153,454 miles per hour, set by Helios 2 in April 1976.

We ain’t seen nothin’ yet. This is only the first orbit. With each later orbit the spacecraft will zip past the Sun faster, and closer.

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Parker looks back at Earth

8:51 am

Earth and Moon, taken by the Parker Solar Probe

The Parker Solar Probe, flying inward towards its first close fly-by of the Sun, has looked back at the Earth and snapped its picture.

The image was captured by the WISPR (Wide-field Imager for Solar Probe) instrument, which is the only imaging instrument on board Parker Solar Probe. During science phases, WISPR sees structures within the Sun’s atmosphere, the corona, before they pass over the spacecraft.

…Zooming in on Earth reveals a slight bulge on the right side: that is the Moon, just peeking out from behind Earth. At the time the image was taken, Parker Solar Probe was about 27 million miles from Earth.

The importance of this image is that it demonstrates that the spacecraft’s camera is working properly, and that the spacecraft itself can point accurately.

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Sunspot update September 2018: Minimum!

9:58 am

NOAA yesterday released its monthly update of the solar cycle, covering sunspot activity for September 2018. As I have done every month since this website began in July 2011, I am posting it below, annotated to give it some context.

Sunspot activity on the Sun in September dropped slightly from August. More significantly, the activity continues to match closely the weak activity seen in 2008, when the Sun last went through its last solar minimum. We are unquestionably now in the new minimum, and its arrival in the past few months makes the now-ending solar cycle about one to two years shorter than predicted.

September 2018 sunspot activity

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

As I noted last month, the NOAA graph is now getting very close to its right edge, which ends in December 2019. They will very soon have to update this graph so that it can take us into the next solar cycle.

What that new cycle will bring will be the next mystery. I have been following this cycle now since its unusual beginning, with a solar minimum much much longer and more inactive than any solar scientist had ever expected. We can only guess at the surprises the Sun will give us in the coming decade, especially since the science of solar sunspot activity remains superficial and in its infancy. We do not really understand why the Sun’s activity fluctuates. Nor do we understand why it periodically stops producing sunspots for long periods, resulting in what solar scientists call a grand minimum.

There are some scientists who think another grand minimum is coming. We shall have to wait and see. I certainly am going to follow their upcoming observations, as this work remains one of the great scientific studies humans are presently pursuing.

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Data from Voyager 2 suggests it is entering interstellar space

7:50 pm

New data since August from Voyager 2 now suggests it is finally leaving the heliosphere of the solar system and entering interstellar space.

Since late August, the Cosmic Ray Subsystem instrument on Voyager 2 has measured about a 5 percent increase in the rate of cosmic rays hitting the spacecraft compared to early August. The probe’s Low-Energy Charged Particle instrument has detected a similar increase in higher-energy cosmic rays.

Cosmic rays are fast-moving particles that originate outside the solar system. Some of these cosmic rays are blocked by the heliosphere, so mission planners expect that Voyager 2 will measure an increase in the rate of cosmic rays as it approaches and crosses the boundary of the heliosphere.

In May 2012, Voyager 1 experienced an increase in the rate of cosmic rays similar to what Voyager 2 is now detecting. That was about three months before Voyager 1 crossed the heliopause and entered interstellar space.

The scientists warn that there is great uncertainty here, and that the actual transition into interstellar space might take longer than with Voyager 1 since Voyager 2 is traveling in a different direction and is leaving during a different time in the solar cycle.

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All instruments check out on the Parker Solar Probe

9:24 am

The initial check out of the Parker Solar Probe, now on its way to the Sun, has shown all instruments are functioning properly.

“All instruments returned data that not only serves for calibration, but also captures glimpses of what we expect them to measure near the Sun to solve the mysteries of the solar atmosphere, the corona,” said Nour Raouafi, Parker Solar Probe project scientist at the Johns Hopkins University Applied Physics Lab in Laurel, Maryland.

The mission’s first close approach to the Sun will be in November 2018, but even now, the instruments are able to gather measurements of what’s happening in the solar wind closer to Earth.

The spacecraft will make its first fly-by of Venus in October.

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Update on the Parker Solar Probe

8:49 am

Link here. The press release notes that the spacecraft’s instruments are one by one being made operational without problem and that it has also successfully completed a second course adjustment.

The release also provided a link to a page which will shows the probe’s present location. This is useful, as it also shows the probe’s position in relation to the Sun, Venus, and the Earth.

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Sunspot update for August 2018: The slide to minimum

12:28 pm

As it does the first Sunday of each month, yesterday NOAA posted its monthly update of the solar cycle, covering sunspot activity for August 2018. And as I do every month, I am posting it below, annotated to give it some context.

The Sun in August had a slight uptick in sunspot activity, but not a very significant one. As such, the slide to solar minimum continues. Right now the lack of sunspot activity in 2018 is heading to match or even exceed 2007, the year in which the previous solar minimum began.

August 2018 sunspot activity

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

If you look at the original graph at NOAA, you will see that we are getting very close to the right edge of the graph. I expect that sometime in the next few months NOAA will update the graph, a necessary act that will in one sense be a shame, as they have been adding monthly updates to this graph since the beginning of the last solar minimum. This has allowed everyone to see a standard visual, month to month, for comparing solar activity. It has also allowed me to annotate the graph properly to show how the 2007 and 2009 predictions held up against actual activity. Once the graph changes it will be more difficult to do this.

Anyway, it is very clear we are entering solar minimum, and that the solar cycle we are now completing will be both a short and weak cycle. What happens next is really the big question. Will the Sun sunspot activity recover? Or will we enter the first grand minimum since the 1600s? Either way, for solar scientists the coming years are going to be very exciting.

Posted on interstate 10 going from Tucson to Phoenix, on the way to the wooded northern forests of Arizona, where Diane and I will spend a couple of days visiting friends at their upstate cabin/home.

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Parker makes first course adjustment

9:29 am

The Parker Solar Probe successfully made its first mid-course correction burn yesterday.

Spacecraft controllers at the mission operation center initiated the two-part TCM-1 [trajectory correction maneuver] beginning at 6:00 a.m. EDT on Aug. 19 with a 44-second burn of the engines. The majority of the engine firing, which lasted just over seven minutes, began at 6:00 a.m. EDT on Aug. 20.

The spacecraft is now traveling at almost forty thousand miles per hour, easily enough to escape the solar system. Its course however is such that it will instead zip past the Sun, at closer distances after each orbit and Venus flyby.

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Sunspot update for July 2018: The Sun flatlines!

10:50 am

Yesterday NOAA posted its monthly update of the solar cycle, covering sunspot activity for July 2018. As I do every month, I am posting it below, annotated to give it some context.

This might be the most significant month of solar activity that has been observed since Galileo. Except for two very short-lived and very weak sunspots that observers hardly noted, the Sun was blank for entire month of July. This has not happened since 2009, during the height of the last solar minimum.

What makes this so significant and unique is that it almost certainly signals the return of the next solar minimum, a return that comes more than a year early. The solar cycle the Sun is now completing has only been ten years long. It is also one of the weakest in more than a hundred years. This combination is unprecedented. In the past such a weak cycle required a long cycle, not a short one.
» Read more

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Sunspot update for June 2018: Activity increases again

5:56 pm

NOAA today posted its monthly update of the solar cycle, covering sunspot activity for June 2018. Below is this month’s annotated graph.

For the third straight month the Sun showed a small increase in sunspot activity. The pattern also continued to follow the two-week-on/two-week-off pattern of activity caused by the Sun’s 27-day rotation, as I described in my update last month.

June 2018 sunspot activity

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction. The yellow line compares the present activity with the activity during solar minimum in 2008 and 2009.

This pattern is continuing. As of today, there have been no sunspots since June 28, almost two weeks. I would not be surprised if some sunspots appeared within the next week, especially because today’s image of the Sun from Solar Dynamic Observatory shows bright faculae rotating into view. Faculae are, like sunspots, a sign of solar magnetic activity. The two usually go together.

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Sunspot update for April 2018: Heading into solar minimum

9:00 am

On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for April 2018. Below is my annotated version of that graph.

While there was an uptick in sunspots in April, compared to the almost complete inactivity in March (the least active month for sunspots in a decade), the uptick did little to change the general trend. Sunspot activity is now comparable to what we saw in early 2008 (as indicated by the yellow line). This was just before the arrival of the previous solar minimum, which happened to also be one of the longest and deepest on record.

» Read more

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Issue with thermometers on Parker Solar Probe

8:56 am

As NASA prepares the Parker Solar Probe for its summer launch, engineers are reviewing an issue with the spacecraft’s thermometers.

As those preparations continue, officials are studying problems with devices known as platinum resistance thermometers that are part of the spacecraft’s thermal control system. Those devices have suffered a higher-than-expected failure rate, according to a presentation at an April 5 meeting of NASA’s Heliophysics Advisory Committee.

The thermometers are lightweight, highly sensitive temperature sensors used to help provide feedback to the spacecraft’s cooling system and solar arrays, NASA spokesman Dwayne Brown said April 9. “We put all spacecraft through a rigorous test program to make sure all systems are working as designed and it is normal for a test program to uncover issues.”

“The team is looking very carefully at whether any change is needed,” Peg Luce, acting director of NASA’s heliophysics division, said at the meeting. The issue, she said, was debated “quite significantly” at a review last week to approve the shipment of the spacecraft to Florida, including whether to delay that shipment to study the problem. “There are certain, possible fixes if we need to fix something that could be done at the Cape, so the decision was to go ahead and ship,” she said.

This issue is especially critical as the spacecraft is intended to fly as close as four million miles from the Sun. If these thermometers fail too easily, the spacecraft will not be able to monitor its temperature properly, and it will likely fail much sooner than planned.

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Sunspot update for March 2018: the sun crashes!

11:49 am

It surely looks like the solar minimum has arrived, and it has done so far earlier than expected! On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for March 2018. Below is my annotated version of that graph.

March 2018 was the least active month for sunspots since the middle of 2009, almost nine years ago. In fact, activity in the past few months has been so low it matches the low activity seen in late 2007 and early 2008, ten years ago when the last solar minimum began and indicated by the yellow line that I have added to the graph below. If the solar minimum has actually arrived now, this would make this cycle only ten years long, one of the shortest solar cycles on record. More important, it is a weak cycle. In the past, all short cycles were active cycles. This is the first time we have seen a short and weak cycle since scientists began tracking the solar cycle in the 1700s, following the last grand minimum in the 1600s when there were almost no sunspots.
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Sunspot update for February 2018

12:25 pm

It’s time for my monthly sunspot update. On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for February 2018. Below the fold is my annotated version of that graph.

Sunspot activity in February continued the low activity seen in November, December, and January, with November 2017 still the most inactive month for sunspots since the middle of 2009. In fact, the low activity we are seeing now is somewhat comparable to the low activity seen during the ramp down to solar minimum in the first half of 2008. By the end of that year we had hit solar minimum, the deepest and longest in a hundred years, suggesting that we might even hit solar minimum before the end of this year. That would have this happen at least a year earlier than all predictions.
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